SO much depends on what state you're in. In Texas, the standard child support is computed based on a percentage of the father's income (30% for three kids like we have). My income doesn't play into it at all. I've been told that in Indiana, an increase in the mother's income means a decrease in child support, which I find abhorrent (were the couple still married, an increase in the mother's income would mean a raised standard of living for the family as a whole; it should IMO be the same after a divorce).
Now, we need to define a couple of terms here. And again, this is going to vary state-by-state. The standard here is joint legal custody. This means that both parents have equal say over issues like education, religion, & medical care when the children are in their possession. However, one parent--typically the mother, although the technical legal criterion is 'best interests of the child', will also have primary physical custody, along with the sole right to determine the children's residence. Along with this, you usually have the standard visitation order, which is the 1st, 3rd, & 5th (if applicable) weekend of the month, as well as one weekday evening, a month during the summer, & alternating holidays. This is what the court defaults to without a good reason (or agreement) to do otherwise.
Now, 50/50 custody of course is the children living with each parent literally half the time. There's no primary physical custody here. Kids are typically switched over every week or two, or every month. I don't know anyone here (in TX) who has that. It's generally something both parents have to agree to. I don't know how it is in other states though. I think, however, it's unusual enough that no judge is likely to force it. You can make an excellent argument that it would not be in the kids' best interests, especially if they are very young.
Child support in a 50/50 custody arrangement is usually lowered here, but not eliminated. In fact, my ex's lawyer shot him in the foot with that issue in mediation. The twit linked the desire for joint physical custody (the 50/50 thing) with paying less than the state guidelines of child support! So no matter how it was meant, he made my ex look like a greedy b-----d.
Again, though, it's something that varies WIDELY by state. I cannot emphasize that enough. I understand the desire to be anonymous, but it would really help if you shared your state, because there's a good chance someone here is where you are and can give you an accurate answer.
Sabra: Mama to Bobbie (3/02), Linda (1/04), Esther (10/05), Marie (11/10), Douglas (11/12), & Psalm (09/14; in Heaven)